Question

solve the system algebraically y=x^2, 9x-y=20

Answer 1

second equation says \[y=9x-20\]
replace in first equation to get
\[9x-20=x^2\]
\[x^2-9x+20=0\]
\[(x-4)(x-5)=0\]
\[x=4\]
\[x=5\]